Combinations of technology in US patents, 1926–2009: a weakening base for future innovation?

In combinatorial models of innovations, new technologies are built from combinations of pre-existing technological components. Researchers learn which components work well together by observing previously successful combinations and the pool of ideas can be ‘fished out’, i.e. exhausted, if it is not ‘restocked’ by the discovery of novel connections. We first show US patents have made increasingly less novel connections among technological constituents since the 1950s, and that the number of technological fields to which these connections are applicable has stopped growing since the 1980s. We then estimate the parameters of an ideas production function, and find parameter estimates consistent with technology fields being fished out if not continually restocked by the discovery of novel connections between technological components. We use the ideas production function to estimate the number of new patent applications induced by each patent granted between 1926 and 2001, and show this number has trended downward since the 1940s.     

Inflation,real economic growth and unemployment expectations: an empirical analysis based on the ECB survey of professional forecasters

Expectations are at the centre of modern macroeconomic theory and policymakers. In this article, we examine the predictive ability and the consistency properties of macroeconomic expectations using data of the European Central Bank (ECB) Survey of Professional Forecasters (SPF). In particular, we provide evidence on the properties of forecasts for three key macroeconomic variables: the inflation rate, the growth rate of real gross domestic product and the unemployment rate.     

土地整治对中国粮食产出稳定性的贡献

研究目的:研究土地整治对粮食产出稳定性的贡献,为制定合理高效的土地整治政策,促进粮食增产稳产提供依据。研究方法:采用H-P滤波法实证分析中国粮食产量的波动性及增长趋势,然后基于C-D生产函数,分别建立趋势产量和波动强度面板回归模型,分析土地整治对粮食产出稳定性的影响。研究结果:(1)粮食作物播种面积、农业机械总动力、农用化肥施用量均对粮食长期趋势产生不同程度促进作用;农业劳动力对主产区粮食长期趋势影响显著为负,对非主产区却有正向影响。(2)土地整治面积和单位面积投资额均降低了全国及主产区粮食产量的波动程度,土地整治规模在全国和主产区的影响系数分别为-1.4162和-2.2215;单位土地整治面积投资额在全国和主产区的影响系数分别为-0.7589和-1.3509。(3)土地整治新增耕地面积对全国和主产区的粮食产量波动强度影响为正,影响系数分别为0.8018和1.3931。可能是通过土地整治新增的耕地质量较低,产出不高,导致了粮食产量波动。土地整治投入在非主产区均表现为不显著。研究结论:应继续推进尤其是主产区的土地整治项目实施,加大土地整治投资强度,建立长期稳定的投入机制,合理使用整治资金,注重提高新增耕地质量和综合生产能力,同时将土地整治投入和管理机制与农业生产系统运行机制、自然因素等有效结合,并制定差别化区域政策,以保障粮食增产稳产和区域协调发展。     

Antecedents of the propensity to learn management practices and their impacts on firm outcomes in emerging markets: A Bayesian Model Averaging approach

This article explores the factors that motivate firms to learn new management practices. The hypotheses are empirically tested using a representative sample of 3676 small, medium and large firms from four South Asian countries and across all main sectors of economic activity. Given that we know little about the antecedents of the propensity to learn management practices in emerging markets, the study employs Bayesian Model Averaging approach to overcome the potential issue of model uncertainty. The results reveal that market competition, resource allocation towards internal and external R&D, good quality mobile network coverage and the use of external certified financial auditors have all positive and significant effects on the propensity to learn management practices. The results also suggest that private intellectual property rights protection in the context of inefficient legal systems can deter firms from learning, perhaps in fear of legal ramifications. Finally, the study shows that firms with a higher propensity of learning management practices are more likely to become profitable while exhibiting higher levels of both potential and actual innovation.     

资本回报率、人力资本投资与收入不平等——基于Galor-Zeira模型的扩展

资本回报率下降对人力资本投资、收入不平等程度有较大影响。本文将可变资本回报率加入Galor-Zeira模型,理论推导发现:收入不平等陷阱并非不可逾越的障碍。当技能劳动力工资高于受教育固定成本时,随着资本回报率下降,接受教育的遗赠临界水平将降低,更多家庭将发现投资人力资本是有利的,稳态的技能劳动力比例将提高。在当前资本回报率下降的大背景下,提高技能劳动力工资、降低受教育成本、对教育贷款实施财政减免优惠、为农村中等教育支出减负和提升农村教育质量、倡导节俭和重视遗赠的文化氛围在长期都有助于提高技能劳动力比重以及缓和收入不平等。     

LABOUR PRODUCTIVITY GROWTH IN THE LONG RUN: JAPAN, 1600–1909

This article examines long-term labour productivity change in Japan from the early seventeenth century to the nineteenth century. We constructed sectoral labour force estimates based on the methodology presented in a previous study, who provided a sectoral GDP series covering the Tokugawa period. Our results show the industrial structure in the Tokugawa period remained relatively stable in comparison with the economy after the Meiji Restoration. Nevertheless, the estimates of sectoral labour productivity suggest expansion of the market economy in Tokugawa Japan influenced the development of industrialisation after the Meiji Restoration.     

Bank Income Diversification,Asset Correlation and Systemic Risk

This paper explores whether the asset correlations among the non-interest activities of banks are the key causes for enhancing the bank diversification-systemic risk nexus. Our empirical evidence indicates that banks' income diversification significantly raises systemic risk. After removing those banks with high asset correlations, the effect of individual banks' diversification on banking systemic risk turns insignificant or even inverse. The results show that high asset correlations among banks could introduce bank failures, thereby leading to higher systemic risk in the financial sector.     

On the closed-form solution of an endogenous growth model with anticipated consumption

This paper derives a closed-form solution of the AK endogenous growth model with logarithmic preferences and anticipated future consumption which enters additively into effective consumption. We get an explicit representation of the time paths of the economic variables in level by resorting to Gaussian Hypergeometric functions. We compare the model with anticipated future consumption to the model with habit formation. The maximum utility attainable in the model with anticipation is shown to be higher than the one attainable in the model with habits. Using the derived explicit expressions, we perform some comparative-dynamics and -statics analyses with respect to relevant parameters. Numerical simulations complement the theoretical results. Thus, this work provides further support to the usefulness of especial functions in the study of economic dynamics.     

“城居保”对中国农村家庭消费支出异质性实证研究

[目的]全面分析城乡居民基本养老保险制度对农村家庭各项消费支出现状的影响,就进一步完善该项政策和稳定农村消费市场提供重要的理论参考。[方法]文章以消费和储蓄生命周期理论为分析框架,通过选取合理的样本面板数据,运用系统GMM回归分析方法探究了城乡居民基本养老保险制度对农村家庭消费支出水平的影响。[结果]财产性收入是影响农民参与城乡居民基本养老保险制度的主要因素以及投保档次的制约因素,作以存量财富为基础的财产性收入要比流量形式存在的财富具有更强抵御风险的能力,即财产性收入在很大程度上可以增加农村家庭对养老保险的依赖程度。另外,城乡居民基本养老保险制度对农村家庭消费能力表现出异质性影响。其中,城乡居民基本养老保险制度对农村家庭生活消费支出、食品性等日常性支出、文体消费支出水平明显要高于对医疗消费支出水平。[结论]国家要加大宣传城乡居民基本养老保险制度的积极和辐射作用,让广大农村家庭能够真正了解这项政策的意图。同时,要逐步破解城乡二元结构等制度性障碍,让更多农村家庭能够享受到与城镇居民相同的养老待遇。     

中国水资源利用秩序评价

水资源利用秩序反映了水资源供给侧效率和需求侧公平的程度。采用秩序模型对我国30个省级行政区2008—2017年的水资源利用状态进行测度,通过测量高低收入人群收入差距的变动状况度量公平程度,使用数据包络分析法将全要素生产率的增长进行分解,从而度量其效率发挥状况,将二者综合,计算水资源总秩序水平。研究结果表明:我国大多数省级行政区水资源利用纵向秩序较好、横向秩序较差,因此应采取措施,以保障水资源利用秩序保持在较高且比较稳定的水平上。